Public preference for COVID-19 vaccines in China: A discrete choice experiment

The effectiveness of coercive measures in motivating vaccination: Evidence from China during the COVID-19 pandemic

Governments worldwide have implemented mandates, restrictions, and other coercive measures to secure adequate vaccine coverage, with the COVID-19 pandemic providing numerous examples. While the ethics and public reception of such measures are matters of heated discussion, their effectiveness in motivating individuals to get vaccinated remains incompletely understood. This study addresses that gap by analyzing data from a 2022 nationwide online survey conducted in China. Respondents recruited through proportional quota sampling to reflect key demographic characteristics of the population were asked to specify their COVID-19 vaccination status and the reason behind their decision. Results reveal that while most respondents reported getting vaccinated voluntarily, 14.6% attributed their vaccination to the government's coercive mobilisation efforts. Moreover, members of the ruling Chinese Communist Party, as well as individuals favouring Western vaccines unavailable in China, were more likely to cite coercive mobilisation as the reason for their vaccination. These findings suggest that coercive measures can motivate a substantial proportion of the population to get vaccinated, especially those closely connected to the political system and those with unmet vaccination preferences. Given the controversy surrounding such measures, this enhanced understanding of their effectiveness could help with formulating targeted policies to combat infectious diseases and safeguard public health.

Willingness to pay for vaccines in China: A systematic review and single-arm Bayesian meta-analysis

The effective implementation of vaccination heavily depends on the society's willingness to pay (WTP). There is currently a dearth of comprehensive evidence about WTP for vaccines in China. This systematic review aims to review studies on the WTP for vaccines, to summarize factors affect WTP in China. Base-case analysis and Sensitivity analysis of WTP for every vaccine were estimated via single-arm Bayesian meta-analysis. A total of 28 studies were included for systematic review. The point estimates and 95% Credible Interval of pooled WTP for influenza and HPV (9-valent) vaccine were $27.409 (23.230, 31.486), $464.707 (441.355, 489.456). Influencing factors to WTP were age, income, peer influence, health condition and etc. Future research should give focus to improving sample representativeness and survey tool, conducting intervention trials, identifying effective methods to promote WTP.

The Evolving Landscape of Discrete Choice Experiments in Health Economics: A Systematic Review

INTRODUCTION

Stakeholder preference evaluations are increasingly emphasized in healthcare policy and health technology assessment. Discrete choice experiments (DCEs) are the most common method for quantifying preferences among patients, the public, and healthcare professionals. While prior reviews (1990-2017) have examined DCE trends, no comprehensive synthesis exists for studies published since 2018. This updated review (2018-2023) provides critical insights into evolving methodologies and global trends in health-related DCEs.

METHODS

A systematic search (2018-2023) of Medline, Embase, and Web of Science identified relevant studies. Studies were screened for inclusion and data were extracted, including details on DCE design and analysis. To enable trend comparisons, the search strategy and extraction items aligned with previous reviews.

RESULTS

Of 2663 identified papers, 1279 met the inclusion criteria, reflecting a significant rise in published DCEs over time. DCEs were conducted globally, with a remarkable increase in publications from Asia and Africa compared with previous reviews. Experimental designs and econometric models have advanced, continuing prior trends. Notably, most recent DCEs were administered online.

DISCUSSION

The rapid growth of DCE applications underscores their importance in health research. While the methodology is advancing rapidly, it is crucial that researchers provide full transparency in reporting their methods, particularly in detailing experimental designs and validity tests, which are too often overlooked. Key recommendations include improving reporting of experimental designs, applying validity tests, following good practices for presenting benefit-risk attributes, and adopting open science practices. Ensuring methodological rigor will maximize the impact and reproducibility of DCE research in health economics.

Socio-demographic differences in citizen' preferences for distributing a scarce, lifesaving resource: A case study using COVID-19 vaccine distribution in Belgium

The COVID-19 pandemic, particularly the period when safe and protective vaccines became available, presented an excellent opportunity to investigate public preferences regarding how to ration a scarce, life-saving resource. It is important to understand which distributive strategies are preferred but, as this is an inherently normative matter, also to which extent different socio-demographic groups hold different opinions. This study assesses the impact of socio-demographic characteristics on preferences for vaccine prioritization during the early stages of the COVID-19 pandemic at the moment when vaccines were not available yet. A representative sample of 2060 Belgians were asked to rank eight prioritization strategies. Based on the rankings, we clustered the eight strategies into five overarching groups. Then, we estimated the potential impact of respondents' socio-demographic characteristics on their preferences towards these five strategies. The ranking exercise shows that the vulnerability strategy (i.e. chronically ill and elderly) is preferred most often (N = 1815) and the market strategy (i.e. individuals who come first or pay the most) by the fewest respondents (N = 116). Preferences for vaccine distribution vary among population subgroups. Women, older or retired individuals, residents of Flanders, those with a positive attitude towards vaccination efforts and/or high vaccination willingness, and those who prefer the government or scientists to decide upon prioritization were more likely to prefer a designated priority strategy (i.e. vulnerability strategy, workers strategy or spreaders). Furthermore, younger respondents, residents of Wallonia, and those previously infected by COVID-19 tended to favour a risk-independent prioritization strategy (i.e. lottery or market strategy) more than others. This study validates the appropriateness of the implemented rationing approaches, by supporting a phased approach in which first vulnerables were vaccinated. However, it also demonstrates that different subgroups had substantially different preferences and the population was in disagreement about what constitutes a fair rationing policy for a scarce, potentially lifesaving resource.

Are we ready for the next pandemic? Public preferences and trade-offs between vaccine characteristics and societal restrictions across 21 countries

In vaccination decisions, individuals must weigh the benefits against the risks of remaining unvaccinated and potentially facing social restrictions. Previous studies have focused on individual preferences for vaccine characteristics and societal restrictions separately. This study aims to quantify public preferences and the potential trade-offs between vaccine characteristics and societal restrictions, including lockdowns and vaccine mandates, in the context of a future pandemic. We conducted a discrete choice experiment (DCE) involving 47,114 respondents from 21 countries between July 2022 and June 2023 through an online panel. Participants were presented with choices between two hypothetical vaccination programs and an option to opt-out. A latent class logit model was used to estimate trade-offs among attributes. Despite some level of preference heterogeneity across countries and respondents' profiles, we consistently identified three classes of respondents: vaccine refusers, vaccine-hesitant, and pro-vaccine individuals. Vaccine attributes were generally deemed more important than societal restriction attributes. We detected strong preferences for the highest levels of vaccine effectiveness and for domestically produced vaccines across most countries. Being fully vaccinated against COVID-19 was the strongest predictor of pro-vaccine class preferences. Women and younger people were more likely to be vaccine refusers compared to men and older individuals. In some countries, vaccine hesitancy and refusal were linked to lower socioeconomic status, whereas in others, individuals with higher education and higher income were more likely to exhibit hesitancy. Our findings emphasize the need for tailored vaccination programs that consider local contexts and demographics. Building trust in national regulatory authorities and international organizations through targeted communication, along with investing in domestic production facilities, can improve vaccine uptake and enhance public health responses in the future.

Investigating the influencing factors of vaccination decisions for newly developed and established vaccines: a comparative study based on latent class logit models in China

Background

The factors influencing vaccination decision-making for newly developed vaccines may be similar to and different from those for established vaccines. Understanding these underlying differences and similarities is crucial for designing targeted measures to promote new vaccines against potential novel viruses.

Objective

This study aims to compare public vaccination decisions for newly developed and established vaccines and to identify the differences and similarities in the influencing factors.

Method

A discrete choice experiment (DCE) was conducted on 1,509 representatives of the general population in China to collect data on preferences for the coronavirus disease 2019 (COVID-19) and influenza vaccines, representing the newly developed and established vaccines, respectively. The latent class logit model was used to identify latent classes within the sample, allowing for an analysis of the factors distinctly influencing choices for both types of vaccines.

Result

Participants valued similar attributes for both vaccines. However, concerns about sequelae were more significant for the newly developed vaccine, while effectiveness was prioritized for the established vaccine. Class membership analysis revealed these differences and similarities were significantly correlated with age, health, yearly household income, acquaintances' vaccination status, and risk perception.

Conclusion

The study highlights the need for tailored communication strategies and targeted vaccination interventions. For the newly developed vaccines, addressing concerns about side effects is more crucial. For long-standing vaccines, emphasizing their effectiveness can enhance uptake more significantly. Engaging healthcare providers and community influencers is essential for both vaccines to increase public confidence and vaccination rates. Clear communication and community engagement are critical strategies for addressing public concerns and misinformation, particularly during periods of heightened concern.

Preferences for COVID-19 Vaccines: Systematic Literature Review of Discrete Choice Experiments

BACKGROUND

Vaccination can be viewed as comprising the most important defensive barriers to protect susceptible groups from infection. However, vaccine hesitancy for COVID-19 is widespread worldwide.

OBJECTIVE

We aimed to systematically review studies eliciting the COVID-19 vaccine preference using discrete choice experiments.

METHODS

A literature search was conducted in PubMed, Embase, Web of Science, Scopus, and CINAHL Plus platforms in April 2023. Search terms included discrete choice experiments, COVID-19, and vaccines and related synonyms. Descriptive statistics were used to summarize the study characteristics. Subgroup analyses were performed by factors such as high-income countries and low- and middle-income countries and study period (before, during, and after the pandemic wave). Quality appraisal was performed using the 5-item Purpose, Respondents, Explanation, Findings, and Significance checklist.

RESULTS

The search yield a total of 623 records, and 47 studies with 53 data points were finally included. Attributes were grouped into 4 categories: outcome, process, cost, and others. The vaccine effectiveness (21/53, 40%) and safety (7/53, 13%) were the most frequently reported and important attributes. Subgroup analyses showed that vaccine effectiveness was the most important attribute, although the preference varied by subgroups. Compared to high-income countries (3/29, 10%), a higher proportion of low- and middle-income countries (4/24, 17%) prioritized safety. As the pandemic progressed, the duration of protection (2/24, 8%) during the pandemic wave and COVID-19 mortality risk (5/25, 20%) after the pandemic wave emerged as 2 of the most important attributes.

CONCLUSIONS

Our review revealed the critical role of vaccine effectiveness and safety in COVID-19 vaccine preference. However, it should be noticed that preference heterogeneity was observed across subpopulations and may change over time.

TRIAL REGISTRATION

PROSPERO CRD42023422720; https://tinyurl.com/2etf7ny7.

Preferences regarding COVID-19 vaccination among 12,000 adults in China: A cross-sectional discrete choice experiment

Understanding public preferences concerning vaccination is critical to inform pandemic response strategies. To investigate Chinese adults' preferences regarding COVID-19 vaccine attributes, we conducted a cross-sectional online survey in 12,000 Chinese adults in June-July, 2021. Participants were requested to answer a series of discrete choice questions related to hypothetical COVID-19 vaccines. Using mixed logit models, our analysis revealed that participants had a higher preference for COVID-19 vaccines with longer duration of protection (coefficient: 1.272, 95% confidence interval [1.016 to 1.529]) and higher efficacy (coefficient: 1.063, [0.840, 1.287]). Conversely, participants demonstrated a lower preference associated with higher risk of rare but serious side-effects (coefficient: -1.158, [-1.359, -0.958]), oral administration (coefficient: -0.211, [-0.377, -0.046]), more doses (coefficient: -0.148, [-0.296, 0.000]) and imported origin (coefficient: -0.653, [-0.864, -0.443]). Moreover, preferences were heterogeneous by individual factors: highly educated participants were more sensitive to the negative vaccine attributes including price (coefficient -0.312, [-0.370, -0.253]) and imported vaccine (coefficient -0.941, [-1.186, -0.697]); there was also substantial heterogeneity in vaccine preferences with respect to age group, marital status, work status, income, chronic diagnosis history, COVID-19 vaccination history and geographic regions. As the first study of examining the public preferences for COVID-19 vaccine in China with a large nationwide sample of 12,000 adults, our results indicate that future vaccine should pose lower risk, possess longer protection period, have higher efficacy, be domestically produced, and have lower costs to increase the COVID-19 vaccination coverage. Our current study findings from this study provide insights and recommendations for not only COVID-19 vaccine design but also vaccine attribute preferences to increase vaccine uptake in potential future pandemics.

Factors influencing individual vaccine preferences for COVID-19 in the Sunyani Municipality, Ghana: An observational study using discrete choice experiment analysis

Background and Aims

There has been hesitancy among people with regard to accepting vaccines, especially that of coronavirus disease-2019 (COVID-19). This hesitancy is aggravated by the different vaccine alternatives available and what one considers before choosing a particular vaccine. The aim of this article was to investigate some driving factors that can influence an individual's COVID-19 vaccine preference in the presence of other alternatives, using some specific vaccine characteristics.

Methods

Discrete choice questionnaire was designed using the attributes and their corresponding levels to collect data on participants' preference for a COVID vaccine over a period of 12 Weeks in Sunyani, Ghana, with the help of an observational study design. A total of 150 participants receiving Covid-19 vaccines at the University of Energy and Natural Resources Hospital were systematically selected and interviewed. Factors considered included: Efficacy of the vaccine, credibility of the manufacturing company, side effects of the vaccine, and availability of the vaccine. Data was analyzed using the conditional probit of the discrete choice experiment (DCE).

Results

Results from the study using the conditional probit of the discrete choice experiment (DCE) showed efficacy, side effects, and availability as significant attributes for preference. However, there was no preference with respect to the credibility of the manufacturing company. In addition, vaccine availability was not a dis-utility in comparison to the alternatives that are readily available. This disutility was however higher among males than females.

Conclusion

From the study, most respondents preferred a COVID-19 vaccine that is highly efficacious or a vaccine with milder side effect or a vaccine that may not necessarily be readily available. It was also observed that dis-utility is higher among males when it comes to vaccine not being readily available than females as the odds of a female choosing a vaccine that is readily available is much higher compared to their males counterparts.

Assessing the job preferences of senior medical students for mandatory service: a discrete choice experiment

AIM

To investigate the job preferences of senior medical students for mandatory service as general practitioners using discrete choice experiment.

INTRODUCTION

Health workforce is directly associated with health service coverage and health outcomes. However, there is a global shortage of healthcare workers (HCWs) in rural areas. Discrete choice experiments can guide the policy and decision-makers to increase recruitment and retention of HCWs in remote and rural areas by determining their job preferences. The aim of this study is to investigate job preferences of senior medical students for mandatory service as general practitioners.

METHODS

This cross-sectional survey was conducted among 144 medical students. To estimate students' preferences for different levels of job attributes, a mixed logit model was utilised. Simulations of job uptake rates and willingness to pay (WTP) estimates were computed.

FINDINGS

All attributes had an impact on the job preferences of students with the following order of priority: salary, workload, proximity to family/friends, working environment, facility and developmental status. For a normal workload and a workplace closed to family/friends which were the most valued attributes after salary, WTPs were 2818.8 Turkish lira (TRY) ($398.7) and 2287.5 TRY ($323.6), respectively. The preference weights of various job characteristics were modified by gender, the presence of a HCW parent and willingness to perform mandatory service. To recruit young physicians where they are most needed, monetary incentives appear to be the most efficient intervention. Non-pecuniary job characteristics also affected job preferences. Packages of both monetary and non-monetary incentives tailored to individual characteristics would be the most efficient approach.

Vaccination status and self-reported side effects after SARS-CoV-2 vaccination in relation to psychological and clinical variables in patients with multiple sclerosis

The recent SARS-CoV-2 pandemic and the vaccination campaign posed a challenge to patients with autoimmune disease, such as multiple sclerosis (MS). We aimed for investigating whether psychological/sociodemographic/clinical characteristics of MS patients are associated with SARS-CoV-2 vaccination status and self-reported vaccination side effects (SEs). We have asked patients with MS about their willingness to receive recommended standard vaccinations pre-pandemically since June 2019. Between 10/2021 and 01/2022, we surveyed 193 of these MS patients about their current SARS-CoV-2 vaccination status, their perception of vaccination-related SEs, and reasons for and against SARS-CoV-2 vaccination. 75.6% of the patients declared their willingness to receive standard vaccinations before the pandemic. 84.5%, 78.2%, and 13.0% of the patients had received the first, second, and third SARS-CoV-2 vaccination, respectively, until the follow-up survey. The most common reason for not getting vaccinated against SARS-CoV-2 was concern about possible side effects (82.1%), followed by the belief that the vaccines had not been adequately tested (64.3%). Vaccination-related SEs were reported by 52.8% of the patients. Younger age, higher education, lower degree of disability, relapsing disease course, shorter disease duration, not receiving a disease-modifying therapy and higher anxiety and depression levels were associated with the occurrence of certain vaccination-related SEs. Concerns about novel vaccines are widespread among MS patients and necessitate targeted education of the patients, especially to those with more severe psychopathological symptoms (anxiety or depression) and those who are generally skeptical of vaccination.

Vaccine decision making in New Zealand: a discrete choice experiment

BACKGROUND

Vaccine hesitancy is a significant threat to global health. A key part of addressing hesitancy is to ensure that public health messaging prioritises information that is considered important to the public. This study aimed to examine how different vaccine characteristics affect public preferences for vaccines in New Zealand, what trade-offs they are willing to make between different vaccine characteristics, and how their preferences are affected by their vaccine-related conspiracy beliefs and COVID-19 vaccination status.

METHODS

An online discrete choice experiment (DCE) was designed to elicit individual preferences about vaccines using the 1000minds platform. Members of the general population of New Zealand aged ≥ 18 years were invited to complete the DCE. Participants were asked to indicate their preference between two options showing different combinations of vaccine characteristics. Data on sociodemographic characteristics were collected. Beliefs were measured using the vaccine conspiracy beliefs scale (VCBS) with scores ≥ 19 indicating strong vaccine-related conspiracy beliefs. The DCE was analysed using the PAPRIKA method (Potentially All Pairwise RanKings of all possible Alternatives) and preferences compared between respondents with high versus low VCBS scores and vaccinated versus unvaccinated respondents for COVID-19.

RESULTS

A total of 611 respondents from 15 regions completed the DCE. Mean (SD) age was 45.9 (14.7) years with most having had 2 or more doses of the coronavirus vaccine (86%). Mean (SD) VCBS score was 18.5 (12.4) indicating moderate vaccine-related conspiracy beliefs. Risk of severe adverse effects was the most highly valued vaccine characteristic, followed by vaccine effectiveness and duration of protection. Vaccine origin and route of administration were ranked least important. Respondents scoring high on the VCBS placed less value on the effectiveness of vaccines but greater value on development time and total number of doses (p < 0.001). COVID-19 unvaccinated respondents ranked development time and total number of doses more highly than those vaccinated respondents (p < 0.001).

CONCLUSIONS

Risk of severe adverse effects, vaccine effectiveness and duration of protection were rated by the New Zealand public as the top three most important vaccine characteristics. This information is important for informing public health messaging to promote vaccine uptake and inform vaccine decision-making.

Which factors drive the choice of the French-speaking Quebec population towards a COVID-19 vaccination programme: A discrete-choice experiment

OBJECTIVES

The aims of this study were to elicit preferences about the coronavirus disease 2019 (COVID-19) vaccine campaign in the general French-speaking adult Quebec population and to highlight the characteristics of the vaccine campaign that were of major importance.

METHODS

A discrete-choice experiment (DCE) was conducted between April and June 2021, in Quebec, Canada. A quota sampling method by age, gender and educational level was used to achieve a representative sample of the French-speaking adult population. The choice-based exercise was described by seven attributes within a vaccine campaign scenario. A mixed logit (MXL) model and a latent class logit (LCL) model were used to derive utility values. Age, gender, educational level, income and fear of COVID-19 were included as independent variables in the LCL.

RESULTS

A total of 1883 respondents were included for analysis, yielding 22,586 choices. From these choices, 3425 (15.16%) were refusals. In addition, 1159 (61.55%) individuals always accepted any of the vaccination campaigns, while 92 individuals (4.89%) always refused vaccine alternatives. According to the MXL, relative weight importance of attributes was effectiveness (32.50%), risk of side effects (24.76%), level of scientific evidence (22.51%), number of shots (15.73%), priority population (3.60%), type of vaccine (0.61%), and vaccination location (0.28%). Four classes were derived from the LCL model and attributes were more or less important according to them. Class 1 (19.8%) was more concerned about the effectiveness (27.99%), safety (24.22%) and the number of shots (21.82%), class 2 (55.3%) wanted a highly effective vaccine (40.16%) and class 3 (17.6%) gave high value to the scientific evidence (42.00%). Class 4 preferences (7.4%) were more balanced, with each attribute having a relative weight ranging from 1.84% (type of vaccine) to 21.32% (risk of side effects). Membership posterior probabilities to latent classes were found to be predicted by individual factors such as gender, annual income or fear of COVID-19.

CONCLUSIONS

Vaccination acceptance relies on multiple factors. This study allowed assessment of vaccination-specific issues through a choice-based exercise and description of factors influencing this choice by segmenting the sample and drawing profiles of individuals. Moreover, besides effectiveness and safety, a major point of this study was to show the importance given by the general population to the level of scientific evidence surrounding vaccines.

PATIENT OR PUBLIC CONTRIBUTION

A small group of citizens was involved in the conception, design and interpretation of data. Participants of the DCE were all from the general population.

Drug transactions and the dark web: Public perceptions of the locational setting of offenders and support for drug policy outcomes

BACKGROUND

Both legal and extra-legal factors influence judicial and non-judicial opinions about persons who use drugs. Yet, how the locational setting of drug transactions influences public perceptions of drug control policies remains understudied. In particular, the public's view of drug exchanges on the dark web could directly and indirectly influence drug policy, legal decision making, and spending decisions. The study's aim is to identify whether the location of a drug exchange, specifically the dark web, influences public preferences for drug policy and police resourcing.

METHODS

A sample (n = 1359) from the United States of America was recruited and participated in a discrete choice experiment. The participants compared and repeatedly chose across five iterations between two drug offender profiles with nine set features, such as the location of drug transactions, all with randomized levels. The resulting sample included a total of 13,590 contest pairs.

RESULTS

Averaging over the non-locational attributes, respondents indicated that, compared to the dark web, several locational settings for drug exchange (such as the street corner, social media, and an unknown location) needed fewer police resources and offenders were less deserving of longer punishments. No statistically significant difference was found for opinions about harm to communities, and offenders involved in drug exchanges on university campuses were considered more deserving of a substance abuse treatment program than offenders on the dark web.

CONCLUSION

There appears to be a preference for more punitive criminal justice policies for drug transactions occurring on the dark web relative to some other common settings. Such preferences may indicate a novelty effect driven by negative sentiment surrounding the dark web or a perceived deficit in the police's ability to deal with drug crimes on the dark web. These findings suggest that the public may prefer supply-side policing efforts over demand-side policies, which emphasizes harm reduction.

Preferences for public engagement in decision-making regarding four COVID-19 non-pharmaceutical interventions in the Netherlands: A survey study

BACKGROUND

Worldwide, non-pharmaceutical interventions (NPIs) were implemented during the COVID-19 crisis, which heavily impacted the daily lives of citizens. This study considers public perspectives on whether and how public engagement (PE) can contribute to future decision-making about NPIs.

METHODS

An online survey was conducted among a representative sample of the public in the Netherlands from 27 October to 9 November 2021. Perceptions and preferences about PE in decision-making on NPIs to control COVID-19 were collected. Preferences regarding four NPIs were studied: Nightly curfew (NC); Digital Covid Certificate (DCC); Closure of elementary schools and daycares (CED); and physical distancing (1.5M). Engagement was surveyed based on the five participation modes of the IAP2 Spectrum of Public Participation, namely inform, consult, advice, collaborate and empower.

RESULTS

Of the 4981 respondents, 25% expressed a desire to engage in decision-making, as they thought engagement could improve their understanding and the quality of NPIs, as well as increase their trust in the government. Especially for the NPIs DCC and NC, respondents found it valuable to engage and provide their perspective on trade-offs in values (e.g. opening up society versus division in society by vaccination status). Respondents agreed that the main responsibility in decision-making should stay with experts and policy-makers. 50% of respondents did not want to engage, as they felt no need to engage or considered themselves insufficiently knowledgeable. Inform was deemed the most preferred mode of engagement, and empower the least preferred mode of engagement.

CONCLUSION

We reveal large variations in public preferences regarding engagement in NPI decision-making. With 25% of respondents expressing an explicit desire to engage, and considering the benefit of PE in other areas of (public) health, opportunities for PE in NPI decision-making might have been overlooked during the COVID-19 pandemic. Our results provide guidance into when and how to execute PE in future outbreaks.

Factors associated with COVID-19 booster vaccine hesitancy: a nationwide, cross-sectional survey in Japan

OBJECTIVES

COVID-19 vaccine hesitancy/fatigue is increasing as the pandemic enters the endemic phase. The present study aimed to explore current perceptions about COVID-19 booster vaccination among the Japanese public.

STUDY DESIGN

This was a cross-sectional study.

METHODS

This cross-sectional study used data from the Japan COVID-19 and Society Internet Survey conducted in September 2021 and September 2022. The public's perceptions of COVID-19 vaccination and factors associated with COVID-19 booster vaccine hesitancy were analyzed.

RESULTS

In total, 56,735 respondents were included. In the Japan COVID-19 and Society Internet Survey 2021, 75.1% of the participants (21,126/28,118) had completed the primary vaccination series. In the 2022 survey, 74.1% of the respondents (21,216/28,617) completed the primary series of vaccination with booster doses. The proportion of fear toward COVID-19 and obtaining information about COVID-19 has decreased from 2021 to 2022. Factors independently associated with booster vaccine hesitancy were young age (range: 18-29 years; adjusted odds ratio [aOR]: 6.56), history of COVID-19 (aOR: 1.82), distrust of the Japanese government's COVID-19 prevention measures (aOR: 1.55), lack of confidence in COVID-19 vaccine efficacy (aOR: 1.30), lack of confidence in COVID-19 vaccine safety (aOR: 1.62), low reliance on the COVID-19 vaccine (aOR: 1.92), and belief in COVID-19 conspiracy theories (aOR: 1.77).

CONCLUSIONS

Providing clear and trustworthy information is critically important, especially targeted and tailored messages for the young generation, to promoting COVID-19 booster vaccination. Policymakers should therefore develop consistent and transparent communication strategies and the ability to respond promptly and flexibly to mitigate the negative impact of COVID-19 on the public while preparing for the next pandemic.

Jumping the Queue:Willingness to Pay for Faster Access to COVID-19 Vaccines in Seven European Countries

INTRODUCTION

Given the initial shortage of vaccines to protect against coronavirus disease 2019 (COVID-19), many countries set up priority lists, implying that large parts of the population had to wait. We therefore elicited the willingness to pay (WTP) for access to two hypothetical COVID-19 vaccines.

METHODS

Respondents were asked how much they would be willing to pay to get an immediate COVID-19 vaccination rather than waiting for one through the public system. We report data collected in January/February 2021 from the European COVID Survey (ECOS) comprising representative samples of the population in Denmark, France, Germany, Italy, Portugal, the Netherlands, and the UK (N = 7068).

RESULTS

In total, 73% (68.5%) of respondents were willing to pay for immediate access to a 100% (60%) effective vaccine, ranging from 66.4% (59.4%) in the Netherlands to 83.3% (81.1%) in Portugal. We found a mean WTP of 54.36 euros (median 37 euros) for immediate access to the 100% effective COVID-19 vaccine and 43.83 euros (median 31 euros) for the 60% effective vaccine. The vaccines' effectiveness, respondents' age, country of residence, income, health state and well-being were significant determinants of WTP. Willingness to be vaccinated (WTV) was also strongly associated with WTP, with lower WTV being associated with lower WTP. A higher perceived risk of infection, higher health risk, more trust in the safety of vaccines, and higher expected waiting time for the free vaccination were all associated with a higher WTP.

CONCLUSION

We find that most respondents would have been willing to pay for faster access to COVID vaccines (jumping the queue), suggesting welfare gains from quicker access to these vaccines. This is an important result in light of potential future outbreaks and vaccines.

The effect of the earliest COVID-19 outbreak on survival in uninfected advanced NSCLC patients receiving chemotherapy in Jiangsu Province, China: A retrospective cohort study

Coronavirus disease 2019 (COVID-19) is still rampant and uncontrolled across the globe. China's strict epidemic prevention measures have had an impact on the treatment in patients with non-small cell lung cancer (NSCLC). The aim of this study is to explore the impact of the COVID-19 outbreak on the uninfected NSCLC patients. The chemotherapeutic efficacy and survival of 89 uninfected advanced NSCLC patients were retrospectively analyzed. The endpoints were overall survival (OS), progression-free survival (PFS), and response rate. Forty and forty-nine patients with advanced NSCLC received chemotherapy during the COVID-19 outbreak and nonoutbreak periods, respectively. Mean delay time was 12.8 months for COVID-19 outbreak stage versus 5.68 months for nonoutbreak stage (P = .003). There was no significant difference in the rates of chemotherapy delay and discontinuation between the 2 groups (P = .055 and .239). Significant difference was not detected in median OS (15.8 months) for COVID-19 outbreak stage versus 16.0 months for nonoutbreak stage (adjusted hazard ratio, 1.058; 95% confidence interval, 0.593-1.888; P = .849); Median PFS was 7.9 months for COVID-19 outbreak stage versus 10.3 months for nonoutbreak stage (adjusted hazard ratio, 0.878; 95% confidence interval 0.513-1.503; P = .634). There was also no statistical difference in the disease control rate between the 2 groups (P = .137). The earliest COVID-19 outbreak had no significant impact on the PFS and OS in uninfected advanced NSCLC patients receiving chemotherapy. However, the mean delay time of receiving chemotherapy was prolonged during the COVID-19 outbreak.

Evolution of preferences for COVID-19 vaccine throughout the pandemic - The choice experiment approach

In this study, we employ a choice experiment to study individual preferences for COVID-19 vaccines in the US. A unique characteristic of the microdata (N = 5671) is that the survey was conducted in five distinct waves from October 2020 to October 2021. Because of this dynamic feature, it is possible to control for evolving pandemic conditions such as the number of COVID-19 active cases, vaccination uptake, and the frequency of Google searches related to the vaccines. Furthermore, we employ a hybrid choice model to incorporate respondents' attitudes related to their perceived vulnerability to diseases, as well as their perceived health status. The hybrid choice model was extended to incorporate latent classes as well as random effects. We find that the rate of vaccinated individuals in the population actually increases the probability of vaccine hesitancy, and therefore may discourage people to get vaccinated. This may be evidence of free-riding behavior. On the other hand, the number of COVID-19 cases has a positive effect on the probability of getting vaccinated, suggesting that individuals react to the pandemic conditions by taking some protective measures. Google trend data do not seem to have a straightforward effect on the vaccination demand, but it increases consumers' willingness to pay for several vaccine characteristics. With respect to the analyzed attitudes, we find that perceived uninfectability is a significant driver of vaccine hesitancy, probably related to the frequent "natural immunity" argument. In turn, germ aversion has a positive effect on the probability of getting vaccinated as well as on the marginal willingness to pay. Finally, health status has a limited effect on whether the individual will decide to vaccinate or not.

Credibility of vaccine-related content on Twitter during COVID-19 pandemic

During national COVID-19 vaccine campaigns, people continuously engaged on Twitter to receive updates on the latest public health information, and to discuss and share their experiences. During this time, the spread of misinformation was widespread, which threatened the uptake of vaccines. It is therefore critical to understand the reasons behind vaccine misinformation and strategies to mitigate it. The current research aimed to understand the content of misleading tweets and the characteristics of their corresponding accounts. We performed a machine learning approach to identify misinformation in vaccine-related tweets, and calculated the demographic, engagement metrics and bot-like activities of corresponding accounts. We found critical periods where high amounts of misinformation coincided with important vaccine announcements, such as emergency approvals of vaccines. Moreover, we found Asian countries had a lower percentage of misinformation shared compared to Europe and North America. Our results showed accounts spreading misinformation had an overall 10% greater likelihood of bot activity and 15% more astroturf bot activity than accounts spreading accurate information. Furthermore, we found that accounts spreading misinformation had five times fewer followers and three times fewer verified badges than fact-sharing accounts. The findings of this study may help authorities to develop strategies to fight COVID-19 vaccine misinformation and improve vaccine uptake.

Preference of young adults for COVID-19 vaccination in the United Kingdom: a discrete choice experiment

OBJECTIVES

To determine preferences for COVID-19 vaccinations in the young adult population in the United Kingdom (UK).

METHOD

A discrete choice experiment survey was conducted in UK young adults. Participants were asked to choose between two hypothetical vaccines the one they preferred the most. Vaccines were defined by five attributes (effectiveness, risk of side effects, duration of protection, number of doses, confidence in available evidence), identified following a systematic literature review and qualitative interviews with 13 young adults. A random parameters logit model, a latent class model, and subgroup analyses were used to identify preferences.

RESULTS

One hundred and forty-nine respondents were included (70% women, mean age 23 years). All five attributes significantly influenced respondents' vaccination decisions. Respondents valued higher effectiveness, lower risk of side effects, longer protection duration, and a smaller number of doses. Based on the range of levels of each attribute, vaccine effectiveness was the most important attribute (relative importance 34%), followed by risk of side effects (32%), and duration of vaccine protection (22%).

CONCLUSIONS

The five investigated vaccine attributes appear to play an important role in young adults' decision-making process. Results of this study may help health authorities designing appropriate strategies in future vaccines campaigns in the younger UK population.

Investigating preferences of the covid-19 vaccine among individuals in Iran: Discrete choice experiment analysis

Background and Aims

This study aimed to estimate the preferences for COVID-19 vaccines among a sample of Iranian adults and to understand the sources of preference heterogeneity.

Methods

A web-based survey was conducted from April to July 2021; out of 1747 participants, 678 completed the survey. Seven key attributes were selected, namely effectiveness, risk of severe side effects, risk of mild side effects, number of doses, duration of protection, location of manufacture, and price. Additionally, conditional logit and mixed logit models were used to analyze the data.

Results

The results of this study indicate that vaccine effectiveness, protective duration, the risk of side effects, and price are the most important factors that influence vaccine preferences. Furthermore, we identified heterogeneity in preferences, indicating that not all individuals respond in the same way to vaccine attributes.

Conclusion

The majority of Iranians prefer to get the Covid-19 vaccine. Policymakers should consider these findings when implementing successful programs. This study contributes to the literature by estimating Iranian respondents' preferences for the Covid-19 vaccine and identifying the heterogeneity in their preferences for vaccine attributes. The findings may also inform future research and policies related to Covid-19 vaccination programs in Iran.

Understanding the role of personal experiences and contextual variables in shaping risk reduction preferences

This article explores how preferences for risk reduction during the COVID-19 pandemic are influenced by personal experiences and contextual variables such as having a close friend or relative who has been infected by the virus (closeness), the severity of the illness (severity), people's own perceptions of being in a risky group (risk group), change in employment status due to the pandemic (employment situation), and vaccination status (vaccination status and altruistic vaccination). We conducted a choice experiment (CE) in Chile, Colombia, and Costa Rica. The attributes of the experiment were risk reduction, latency, and cost. Then, we estimated a mixed logit model to capture preference heterogeneity across the countries. The attributes presented in the CE were statistically significant, with the expected sign in each country. The variables closeness and employment situation presented homogeneous behavior in each country; however, severity, risk group, and vaccination status showed mixed results. We found that preferences were more heterogeneous for the attributes of the CE than for the personal experiences and contextual variables. Understanding the impact of these variables is essential for generating more effective risk reduction policies. For instance, methodologies such as the value of statistical life base their calculations on society's valuation of risk reduction. We provide evidence that the preferences for risk reduction vary due to the everyday situations that individuals face in the context of the pandemic. The latter may cause distortions in the values used to evaluate policies aimed at mitigating the outbreak.

The COVID-19 vaccination decision-making preferences of elderly people: a discrete choice experiment

COVID-19 is a continuing threat to global public health security. For elderly people, timely and effective vaccination reduces infection rates in this group and safeguards their health. This paper adopted an offline Discrete Choice Experiment (DCE) to research the preference for COVID-19 vaccination amongst Chinese adults aged 50 years and above. Through multinomial logistic regression analysis, our DCE leverages five attributes-the risk of adverse reactions, protective duration, injection doses, injection period, and effectiveness-each of which is split into three to four levels. The risk of adverse reaction and the protective duration were demonstrated to be determinants of vaccination preference. Moreover, it was found that socio demographic factors like region, self-health assessment and the number of vaccinated household members can strengthen or weaken the effects of vaccine attributes. In conclusion, the preferences of the elderly population should be considered when developing COVID-19 vaccination programs for this population in China. Accordingly, the results may provide useful information for policymakers to develop tailored, effectively vaccination strategies.

Patients' preferences in dental care: A discrete-choice experiment and an analysis of willingness-to-pay

INTRODUCTION

Dental diseases are a major problem worldwide. Costs are a burden on healthcare systems and patients. Missed treatments can have health and financial consequences. Compared to other health services, dental treatments are only covered in parts by statutory health insurance (SHI). Using the example of dental crowns for a cost-intensive treatment, our study aims to investigate whether (1) certain treatment attributes determine patients' treatment choice, and (2) out-of-pocket payments represent a barrier to access dental care.

METHODS

We conducted a discrete-choice-experiment by mailing questionnaires to 10,752 people in Germany. In presented scenarios the participants could choose between treatment options (A, B, or none) composed of treatment attribute levels (e.g., color of teeth) for posterior (PT) and anterior teeth (AT). Considering interaction effects, we used a D-efficient fractional factorial design. Choice analysis was performed using different models. Furthermore, we analyzed willingness-to-pay (WTP), preference of choosing no and SHI standard care treatment, and influence of socioeconomic characteristics on individual WTP.

RESULTS

Out of n = 762 returned questionnaires (response rate of r = 7.1), n = 380 were included in the analysis. Most of the participants are in age group "50 to 59 years" (n = 103, 27.1%) and female (n = 249, 65.5%). The participants' benefit allocations varied across treatment attributes. Aesthetics and durability of dental crowns play most important roles in decision-making. WTP regarding natural color teeth is higher than standard SHI out-of-pocket payment. Estimations for AT dominate. For both tooth areas, "no treatment" was a frequent choice (PT: 25.7%, AT: 37.2%). Especially for AT, treatment beyond SHI standard care was often chosen (49.8%, PT: 31.3%). Age, gender, and incentive measures (bonus booklet) influenced WTP per participant.

CONCLUSION

This study provides important insights into patient preferences for dental crown treatment in Germany. For our participants, aesthetic for AT and PT as well as out-of-pocket payments for PT play an important role in decision-making. Overall, they are willing to pay more than the current out-of-pockt payments for what they consider to be better crown treatments. Findings may be valuable for policy makers in developing measures that better match patient preferences.

COVID-19 Vaccination Preferences among non-Chinese migrants in Hong Kong: A Discrete Choice Experiment

BACKGROUND

Studies has shown increase COVID-19 vaccination hesitancy among migrant populations in certain settings than the general population. Hong Kong (HK) has a growing migrant population with diverse ethnic backgrounds. Apart from individual level factors little is known about the migrants' preference related to COVID-19 vaccines.

OBJECTIVE

This study aimed to investigate which COVID-19 vaccine-related attributes combined to individual factors may lead to vaccine acceptance or refusal among the migrant population in HK.

METHODS

An online discrete choice experiment (DCE) was conducted among all adults, including Chinese people, non-Chinese Asians (South, South-East and North-East Asians), and non-Asians (Europeans, Americans and Africans) migrants in HK from 26 February to 26 April 2021. The participants were recruited by quota sampling and sent a link to web-survey. The vaccination attributes included in eight choice sets in each of the four blocks were vaccine brand, safety and efficacy, vaccine uptake by people around, professionals' recommendation, vaccination venue, and quarantine exemption for vaccinated travelers. Nested logistic model and latent-class logit (LCL) model were used for statistical analysis.

RESULTS

A total of 208 migrant participants were included with a response rate of 62.1%. Among migrants, participants with longer local residential years (27.7% for 10+ years, 20.6% for 7-9 years, 6.7% for 4-6 years, and 9.7% for below 3 years; P=.03), lower education level (28.3% vs 13.9%, P=.01) and lower income (25.2% vs 13.2%, P=.04) were more likely to refuse COVID-19 vaccination irrespective of vaccination attributes. BioNTech vaccine compared with Sinovac (adjusted odds ratio [AOR]: 1.75, 95% confidence interval [CI]: 1.14-2.68), vaccine with 90% (AOR: 1.44, 95%CI: 1.09-1.91) and 70% efficacy(AOR: 1.21, 95%CI: 1.03-1.44) compared with 50%, vaccine with fewer serious adverse events 1/100,000 compared with 1/10,000 (AOR: 1.12, 95%CI: 1.00-1.24) and quarantine exemption for cross-border travelers(AOR: 1.14, 95%CI: 1.01-1.30) were the vaccine attributes that could increase the likelihood of vaccination among migrants. For individual-level factors, the full-time housemakers (AOR: 0.44, 95%CI: 0.29-0.66), those with chronic conditions (AOR: 0.61, 95%CI: 0.41-0.91) and more children, and those frequently received vaccine-related information from workplace (AOR: 0.42, 95%CI: 0.31-0.57) were found reluctant to accept the vaccine. those with higher income (AOR: 1.79, 95%CI: 1.26-2.52), knowing anyone infected with COVID-19 (AOR: 1.73, 95%CI: 1.25-2.38), having greater perceived susceptibility of COVID-19 infection (AOR: 3.42, 95%CI: 2.52-4.64), received influenza vaccine (AOR: 2.15, 95%CI: 1.45-3.19), and frequently received information from social media (AOR: 1.52, 95%CI: 1.12-2.05) were more likely to accept the vaccine.

CONCLUSIONS

This study implies that migrants have COVID-19 vaccination preference heterogeneity and more targeted and tailored approaches are needed to promote vaccine acceptance for different subgroups of migrant population in Hong Kong. Vaccination promotion strategies are needed for low education and low income migrant groups, migrants with chronic diseases, working migrant population, housemakers and parents.

CLINICALTRIAL

Vaccination or NPI? A conjoint analysis of German citizens' preferences in the context of the COVID-19 pandemic

This research uses discrete choice-based conjoint analysis that elicits the preference structure of German citizens when it comes to their timely intention to vaccinate. The focus is on the trade-offs between pharmaceuticals (vaccine) and "non-pharmaceutical interventions" (NPIs) such as lock-downs and social distancing measures, as well as the value of voluntary versus mandatory compliance to the citizens. Our results highlight three critical insights: (a) value of waiting: at 70% effective vaccine, 1/3 of citizens still would prefer to be vaccinated in the next 6 months rather than immediately; (b) costs of NPI constraints: an effective vaccine may come as a solution to compensate for the costs induced by invasive NPI imposed for an extended period; (c) freedom of choice: voluntary compliance is preferred by citizens over imposed measures whether it relates to vaccination choice, lock-down measures, or work location choice during the pandemic. Backing up those findings in monetary value, a quick shot of a 100% effective vaccination is estimated to be worth in the range of 11,400€. Still, the value of the shot quickly falls to no value when effectiveness drops below 50. At the same time, the cost of imposing protective rules lies in the range of 1500-2500€, depending on the rule analyzed. In comparison, the burden of extra complete lock-down and social distancing is about 775€ per citizen per month. As most current vaccines are being proven to have high efficacy, a strategy that selects the most effective vaccine candidates while emphasizing how the vaccine may stop the pain of lasting lock-downs will be appropriate to nudge the population towards vaccination. Control measures that are too restrictive may be welfare-deteriorating, but enough NPI measures must be recommended as long as vaccination adoption is not sufficiently large.

Loss-framing of information and pre-vaccination consultation improve COVID-19 vaccine acceptance: A survey experiment

Backgrounds

Vaccination remains one of the most effective ways to protect populations from COVID-19 infection, severe conditions, and death. This study aims to examine whether the gain/loss-framing of information, provision of subsidized pre-vaccination physician consultation, and cash incentives can improve COVID-19 acceptance amongst adults.

Methods

A survey experiment was conducted within a broader cross-sectional survey of people aged 18-64 years in Hong Kong, China. The participants were randomly assigned to one of the eight groups derived from full-factorial design of the three strategies with stratification by age and sex. The vaccine acceptance rate was compared between people with and without any of the strategies. The heterogeneous effects of these strategies were identified for those with different perceptions of the pandemics and vaccine in multiple logistic regressions.

Results

The survey experiment collected 1,000 valid responses. It found that loss-framed information and provision of subsidized physician consultation to assess suitability to be vaccinated, can improve vaccine acceptance, while cash incentives did not make a difference. The improvement effect of loss-framing information and physician consultation is stronger among those with higher perceived infection risk and severity of condition, as well as unvaccinated people with lower confidence in vaccine safety.

Conclusions

The findings indicated that individualized loss-framing messages and equitable provision of subsidized pre-vaccination physician consultations can be incorporated in efforts to promote vaccine acceptance and vaccination roll-out speed. However, it remains inconclusive whether and how universal cash incentives may be deployed to support vaccination promotion.

Trade-offs during the COVID-19 pandemic: A discrete choice experiment about policy preferences in Portugal

The need to control the sanitary situation during the COVID-19 pandemic has led governments to implement several restrictions with substantial social and economic impacts. We explored people's trade-offs in terms of their income, life restrictions, education, and poverty in the society, compared to their willingness to avoid deaths. We applied a web-based discrete choice experiment to elicit preferences of the Portuguese citizens for these attributes and computed the marginal rate of substitution in terms of avoided deaths. We recorded 2,191 responses that faced the possibility of having 250 COVID-19 related deaths per day as the worst possible outcome from the choice levels presented. Estimates suggested that individuals would be willing to sacrifice 30% instead of 10% of their income to avoid approximately 47 deaths per day during the first six months of 2021. For the same period, they would also accept 30% of the students' population to become educationally impaired, instead of 10%, to avoid approximately 25 deaths; a strict lockdown, instead of mild life restrictions, to avoid approximately 24 deaths; and 45% of the population to be in risk of poverty, instead of 25%, to avoid approximately 101 deaths. Our paper shows that avoiding deaths was strongly preferred to the remaining societal impacts; and that being a female, as well as working on site, led individuals to be more averse to such health hazards. Furthermore, we show how a DCE can be used to assess the societal support to decision-making during times of crisis.

Cueing quality: Unpacking country-of-origin effects on intentions to vaccinate against COVID-19 in Taiwan

While existing studies have reported and recognized country-of-origin effects on the intentions to vaccinate against COVID-19 among individual citizens in some countries, the causal mechanism behind such effects to inform public health policymakers remain unexplored. Adding up a quality cue explanation for such effects to the existing literature, the authors argue that individual consumers are less willing to get a vaccine designed and manufactured by a country with a significantly lower quality perception than other countries. A survey experiment that recruited a nationally representative sample of Taiwanese adults (n = 1951) between December 13, 2020 and January 11, 2021 was designed and conducted to test the argument. We find that all else equal, Taiwanese respondents were on average less likely to express stronger willingness to take a vaccine from China than from the US, Germany, and Taiwan. Furthermore, even when the intrinsic quality of the vaccine was held constant by the experimental design, respondents still had a significantly lower quality perception of the vaccine from China, both in terms of perceived protection and severe side effects. Further evidence from casual mediation analyses shows that about 33% and 11% of the total average causal effects of the "China" country-of-origin label on vaccine uptake intention were respectively mediated through the perceived efficacy of protection and perceived risk of experiencing severe side effects. We conclude that quality cue constitutes one of many casual mechanisms behind widely reported country-of-origin effects on intention to vaccinate against COVID-19.

Population preferences for non-pharmaceutical interventions to control the SARS-CoV-2 pandemic: trade-offs among public health, individual rights, and economics

PROBLEM

Policymakers must decide on interventions to control the pandemic. These decisions are driven by weighing the risks and benefits of various non-pharmaceutical intervention alternatives. Due to the nature of the pandemic, these decisions are not based on sufficient evidence regarding the effects, nor are decision-makers informed about the willingness of populations to accept the economic and health risks associated with different policy options. This empirical study seeks to reduce uncertainty by measuring population preferences for non-pharmaceutical interventions.

METHODS

An online-based discrete choice experiment (DCE) was conducted to elicit population preferences. Respondents were asked to choose between three pandemic scenarios with different interventions and impacts of the Corona pandemic. In addition, Best-worst scaling (BWS) was used to analyze the impact of the duration of individual interventions on people's acceptance. The marginal rate of substitution was applied to estimate willingness-to-accept (WTA) for each intervention and effect by risk of infection.

RESULTS

Data from 3006 respondents were included in the analysis. The DCE showed, economic effect of non-pharmaceutical measures had a large impact on choice decisions for or against specific lockdown scenarios. Individual income decreases had the most impact. Excess mortality and individual risk of infection were also important factors influencing choice decisions. Curfews, contact restrictions, facility closures, personal data transmissions, and mandatory masking in public had a lesser impact. However, significant standard deviations in the random parameter logit model (RPL) indicated heterogeneities in the study population. The BWS results showed that short-term restrictions were more likely to be accepted than long-term restrictions. According to WTA estimates, people would be willing to accept a greater risk of infection to avoid loss of income.

DISCUSSION

The results can be used to determine which consequences of pandemic measures would be more severe for the population. For example, the results show that citizens want to limit the decline in individual income during pandemic measures. Participation in preference studies can also inform citizens about potential tradeoffs that decision-makers face in current and future decisions during a pandemic. Knowledge of the population's preferences will help inform decisions that consider people's perspectives and expectations for the future. Survey results can inform decision-makers about the extent to which the population is willing to accept certain lockdown measures, such as curfews, contact restrictions, lockdowns, or mandatory masks.

Impacts of Vaccination on International Trade During the Pandemic Era

This paper examines how COVID-19 vaccinations change international trade. We analyze monthly level trade data from January 2020 to March 2022 that cover the bilateral exports from 40 reporting countries to 220 partner countries. Our findings can be summarized as follows. On average, the effects of vaccination rates in importing and exporting countries on exports were found to be insignificant. When considering the income level, we also did not find significant effects of vaccination rates in high- and low-income importing countries on exports. In contrast, the rise of vaccination rates in low-income exporting countries significantly increased their exports though no significant increase in exports was detected when vaccination rates rose in high-income exporting countries. These results imply that since low-income countries are mainly engaged in labor-intensive industries, the relaxation of lockdown orders (i.e., movement and gathering restrictions) driven by the rise of vaccination rates plays a crucial role in production activities in low-income countries.

Stated choice analysis of preferences for COVID-19 vaccines using the Choquet integral

We investigate preferences for COVID-19 vaccines using data from a stated choice survey conducted in the US in March 2021. To analyse the data, we embed the Choquet integral, a flexible aggregation operator for capturing attribute interactions under monotonicity constraints, into a mixed logit model. We find that effectiveness is the most important vaccine attribute, followed by risk of severe side effects and protection period. The attribute interactions reveal that non-pecuniary vaccine attributes are synergistic. Out-of-pocket costs are independent of effectiveness, incubation period, and mild side effects but exhibit moderate synergistic interactions with other attributes. Vaccine adoption is significantly more likely among individuals who identify as male, have obtained a bachelor's degree or a higher level of education, have a high household income, support the democratic party, had COVID-19, got vaccinated against the flu in winter 2020/21, and have an underlying health condition.

Parental preference for Haemophilus influenzae type b vaccination in Zhejiang Province, China: A discrete choice experiment

Background

China is the only country in the world that has not included the Haemophilus influenzae type b (Hib) vaccine in its National Immunization Program, making it more difficult to eliminate Hib-related diseases through Hib vaccination. It is necessary to study parental preferences for Hib vaccination to optimize vaccine promotion strategies in China.

Objective

This study aimed to investigate Chinese parental preference for five attributes of Hib vaccination, i.e., the place of origin, effectiveness, adverse event, doctors' recommendation, and the price of full vaccination when making a decision to vaccinate their children under 2 years old.

Methods

A cross-sectional survey was conducted in two cities in Zhejiang Province from November to December in 2020 using a discrete choice experiment (DCE). A mixed logit model was used to estimate participating parents' preference for Hib vaccination attributes included in the DCE. Subgroup analysis and probability analysis were also conducted to capture the heterogeneity and trade-off of parental preference for Hib vaccination.

Results

Data from 6,168 observations were included in the analyses. Parents of children are, on average, more likely to voice a positive preference for Hib vaccination. Such attributes of Hib vaccination as effectiveness and doctor's recommendation have a significant positive influence on parents' preference for Hib vaccination, while imported vaccines, adverse events, and the price of full vaccination have a significant negative influence on parents' preference. Parents with different demographic characteristics also existed heterogeneities in preference for Hib vaccination. Parents will make a trade-off on price if the Hib vaccine has a good performance on effectiveness and safety.

Conclusion

The study found that, regardless of the place of origin of the Hib vaccine, parents with children under 2 years old prefer to compromise on price if the vaccine has a better effectiveness and safety profile. A proactive recommendation from doctors would strengthen their willingness for Hib vaccination. These findings help aid the development of communication strategies with parents for Hib vaccination in China.

What drives the acceptability of restrictive health policies: An experimental assessment of individual preferences for anti-COVID 19 strategies

The public acceptability of a policy is an important issue in democracies, in particular for anti-COVID-19 policies, which require the adherence of the population to be applicable and efficient. Discrete choice experiment (DCE) can help elicit preference ranking among various policies for the whole population and subgroups. Using a representative sample of the French population, we apply DCE methods to assess the acceptability of various anti-COVID-19 measures, separately and as a package. Owing to the methods, we determine the extent to which acceptability depends on personal characteristics: political orientation, health vulnerability, or age. The young population differs in terms of policy preferences and their claim for monetary compensation, suggesting a tailored policy for them. The paper provides key methodological tools based on microeconomic evaluation of individuals' preferences for improving the design of public health policies.

Student COVID-19 vaccination preferences in China: A discrete choice experiment

Objective

This study uses a discrete choice experiment (DCE) questionnaire to investigate student vaccination preferences for both intrinsic and extrinsic attributes.

Methods

A two-part DCE questionnaire was distributed to 1,138 students through face-to-face interviews at vaccination centers in Qingdao, China. Conditional logit models were used to understand student preference trade-offs. Mixed logit models (MLM) and sub-group analysis were conducted to understanding student preference heterogeneity.

Results

We found that students preferred vaccines with fewer side effects (β = 0.845; 95% CI, 0.779-0.911), administered through third level health facilities (β = 0.170; 95% CI, 0.110-0.230), and had at least 1 year duration of protection (β = 0.396; 95% CI, 0.332-0.461. Higher perception of COVID-19 risks (β = 0.492; 95% CI, 0.432-0.552) increased the likelihood of student vaccination uptake. Surprisingly, vaccine effectiveness (60%) and percentages of acquaintances vaccinated (60%) reduced vaccination utility, which points to free-rider problems. In addition, we find that student study majors did not contribute to preference heterogeneity, and the main disparities in preferences were attributed to student risk tolerances.

Conclusion

Both intrinsic and extrinsic attributes were influential factors shaping student preferences for COVID-19 vaccines. Our results inform universities and local governments across China on targeting their vaccination programs.

Malaysian public preferences and decision making for COVID-19 vaccination: A discrete choice experiment

BACKGROUND

Low vaccine uptake has the potential to seriously undermine COVID-19 vaccination programs, as very high coverage levels are likely to be needed for virus suppression to return life to normal. We aimed to determine the influence of vaccine attributes (including access costs) on COVID-19 vaccination preferences among the Malaysian public to improve national uptake.

METHODS

An online Discrete Choice Experiment (DCE) was conducted on a representative sample of 2028 Malaysians. Respondents were asked to make vaccination decisions in a series of hypothetical scenarios. A nested, mixed logit model was used to estimate the preferences for vaccination over vaccine refusal and for how those preferences varied between different sub-populations. The attributes were the risk of developing severe side effects of the vaccine, vaccine effectiveness, vaccine content, vaccination schedule, and distance from home to vaccination centre.

FINDINGS

Reported public uptake of COVID-19 vaccination was primarily influenced by the risk of developing severe side effects (b = -1·747, 95% CI = -2·269, -1·225), vaccine effectiveness (b = 3·061, 95% CI = 2·628, 3·494) and its Halal status (b = 3·722, 95% CI = 3·152, 4·292). Other factors such as appointment timing and travel distance to the vaccination centre also had an effect on vaccine uptake. There was substantial heterogeneity in preferences between different populations, particularly for age groups, ethnicity, regions, and underlying health conditions.

INTERPRETATION

Perceived effectiveness and side effects are likely to affect COVID-19 vaccine uptake in Malaysia. Halal content is critical to Malays' vaccination choices. Reducing the physical distance to vaccination centres, particularly in rural areas where uptake is lower, is likely to improve uptake.

FUNDING

Ministry of Health Research Grant from the Malaysian government [NIH/800-3/2/1 Jld.7(46), grant reference no: 57377 and warrant no: 91000776].

Willingness to pay for COVID-19 vaccines in Jordan: Applying the health belief model

BACKGROUND

To date, there is no effective treatment for COVID-19. Vaccines are effective and safe strategies to control the pandemic.

OBJECTIVE

To measure consumers' maximum willingness to pay (WTP) for COVID-19 vaccines in Jordan and to identify the predictors of WTP.

METHOD

An online survey was used to collect data related to sociodemographic factors and constructs from the Health Belief Model (HBM). The contingent valuation method using the payment card approach was used, whereby the respondents were asked to choose their maximum WTP value from a range of 5-200 Jordanian Dinar (JOD). The maximum WTP values were then categorized into several groups, and an ordered logistic model was used to generate adjusted odds ratios and estimate the significant predictors of maximum WTP.

RESULTS

A total of 3116 respondents completed the survey. More than half of the sample were not willing to pay out of pocket for the vaccine (57%). Among the respondents who were willing to pay any amount above zero, the mean maximum WTP was 28.1 JOD (39.63 USD), and the median WTP was 20 JOD (28.21 USD). The significant predictors of higher WTP values were being of younger age, higher income, being a healthcare provider, having one or more chronic diseases, previous history of receiving the seasonal influenza vaccine, having a family member/friend who has died from the COVID-19, lower perceived risk of the vaccine, higher perceived benefits of the vaccine, and having been recommended to get the vaccine.

CONCLUSION

It is recommended to continue providing the vaccine free of charge to increase its uptake. Educational campaigns should focus on refuting myths related to the vaccine and promoting the benefits of receiving the vaccine in slowing the spread of the pandemic, and improving the economy. Healthcare providers' recommendations have the potential to increase WTP for the vaccine.

Perceived health literacy and COVID-19 vaccine acceptance among Chinese college students: A mediation analysis

BACKGROUND

Although COVID-19 vaccines hold the potential to dramatically alter the COVID-19 pandemic, vaccine hesitancy remains a serious threat to the management and control of COVID-19 infections. Vaccination of young adults plays a crucial role in achieving herd immunity. However, the determinants of COVID-19 vaccine acceptance among the youth in China have not been fully explored. Our study aims to investigate the direct and indirect effects of perceived health literacy on COVID-19 vaccine acceptance.

METHODS

This survey was conducted among Chinese college students during September and October, 2020. COVID-19 vaccine acceptance was defined as the likelihood that participants would get a COVID-19 vaccine. A mediation analysis was employed to explore the direct and indirect effects of perceived health literacy on COVID-19 vaccine acceptance.

RESULTS

A total of 2,587 college students were included in our study. The results of the survey revealed that the majority (80.40%) of the participants expressed high COVID-19 vaccine acceptance. After controlling for demographic characteristics, the relationship between perceived health literacy and COVID-19 vaccine acceptance was mediated by positive attitudes toward general vaccination (std.β = 0.004, p = 0.037) and self-efficacy of COVID-19 vaccine (std.β = 0.053, p < 0.001).

CONCLUSIONS

The findings suggest that interventions targeting health literacy to promote COVID-19 vaccination coverage might consider placing greater emphasis on enhancing the positive attitude towards and self-efficacy of vaccines among youth.

Applications of discrete choice experiments in COVID-19 research: Disparity in survey qualities between health and transport fields

Published choice experiments linked to various aspects of the COVID-19 pandemic are analysed in a rapid review. The aim is to (i) document the diversity of topics as well as their temporal and geographical patterns of emergence, (ii) compare various elements of design quality across different sectors of applied economics, and (iii) identify potential signs of convergent validity across findings of comparable experiments. Of the N = 43 published choice experiments during the first two years of the pandemic, the majority identifies with health applications (n = 30), followed by transport-related applications (n = 10). Nearly 100,000 people across the world responded to pandemic-related discrete choice surveys. Within health applications, while the dominant theme, up until June 2020, was lockdown relaxation and tracing measures, the focus shifted abruptly to vaccine preference since then. Geographical origins of the health surveys were not diverse. Nearly 50% of all health surveys were conducted in only three countries, namely US, China and The Netherlands. Health applications exhibited stronger pre-testing and larger sample sizes compared to transport applications. Limited signs of convergent validity were identifiable. Within some applications, issues of temporal instability as well as hypothetical bias attributable to social desirability, protest response or policy consequentiality seemed likely to have affected the findings. Nevertheless, very few of the experiments implemented measures of hypothetical bias mitigation and those were limited to health studies. Our main conclusion is that swift administration of pandemic-related choice experiments has overall resulted in certain degrees of compromise in study quality, but this has been more so the case in relation to transport topics than health topics.

Public Preferences and Willingness to Pay for a COVID-19 Vaccine in Iran: A Discrete Choice Experiment

BACKGROUND AND OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic is a major international threat and vaccination is the most robust strategy to terminate this crisis. It is helpful for policymakers to be aware of community preferences about vaccines. The present study aims to investigate the public's preferences and willingness to pay for the COVID-19 vaccine in Iran.

METHODS

This research is a cross-sectional study performed using a discrete choice experiment for a sample of the public population of several provinces of Iran in 2021. The samples were divided into two groups: one group expressed their preferences regarding the vaccine's attributes, and another group expressed their preferences regarding prioritizing individuals to get the vaccine. The discrete choice experiment design included five attributes including effectiveness, risk of severe complications, price, location of vaccine production, and duration of protection related to preferences for vaccine selection and six attributes including age, underlying diseases, employment in the healthcare sector, the rate of virus spread, the necessary job, and cost to the community related to preferences for prioritizing individuals to get the vaccine. A total of 715 individuals completed the questionnaire. The conditional logit regression model was used to analyze the discrete choice experiment data. Willingness to pay for each attribute was also calculated.

RESULTS

The willingness to pay for the COVID-19 vaccine with 90% (70%) efficacy, the risk of severe complications for 1 (5) person per one million people, imported (domestic) vaccine, and 24-month (12-month) duration of protection attributes was about US$71 (US$37). The preference for vaccination for respondents was enhanced by increasing the efficacy and the duration of vaccine protection and decreasing complications and costs. The likelihood of prioritizing individuals to get a vaccination was increased for a person with an underlying disease, employment in the healthcare sector, the necessary job for the community, the high potential for virus spread in the community, and the high cost of death to the community. The age variable was not statistically significant for prioritizing individuals to get the vaccine.

CONCLUSIONS

In the setting of the COVID-19 vaccination program, the public's preferences identified in this study should be considered. The obtained results provide useful information for policymakers to identify individual and social values for an appropriate vaccination strategy.

A Systematic Investigation of American Vaccination Preference via Historical Data

While COVID-19 vaccines are generally available, not all people receive vaccines. To reach herd immunity, most of a population must be vaccinated. It is, thus, important to identify factors influencing people’s vaccination preferences, as knowledge of these preferences allows for governments and health programs to increase their vaccine coverage more effectively. Fortunately, vaccination data were collected by U.S. Census Bureau in partnership with the CDC via the Household Pulse Survey (HPS) for Americans. This study presents the first analysis of the 24 vaccination datasets collected by the HPS from January 2021 to May 2022 for 250 million respondents of different ages, genders, sexual orientations, races, education statuses, marital statuses, household sizes, household income levels, and resources used for spending needs, and with different reasons for not receiving or planning to receive a vaccine. Statistical analysis techniques, including an analysis of variance (ANOVA), Tukey multiple comparisons test, and hierarchical clustering (HC), were implemented to analyze the HPS vaccination data in the R language. It was found that sexual orientation, gender, age, and education had statistically significant influences on the vaccination rates. In particular, the gay/lesbian group showed a higher vaccination rate than the straight group; the transgender group had a lower vaccination rate than either the female or the male groups; older respondents showed greater preference for vaccination; respondents with higher education levels also preferred vaccination. As for the other factors that were not significant enough to influence vaccinations in the ANOVA, notable trends were found. Asian Americans had higher vaccination rates than other races; respondents from larger household sizes had a lower chance of getting vaccinated; the unmarried group showed the lowed vaccination rate in the marital category; the respondents depending on borrowed money from the Supplemental Nutrition Assistance Program (SNAP) showed a lower vaccination rate than people with regular incomes. Concerns regarding the side-effects and the safety of the vaccines were the two major reasons for vaccination hesitance at the beginning of the pandemic, while having no trust in the vaccines and no trust in the government became more common in the later stage of the pandemic. The findings in this study can be used by governments or organizations to improve their vaccination campaigns or methods of combating future pandemics.

Global Prevalence and Potential Influencing Factors of COVID-19 Vaccination Hesitancy: A Meta-Analysis

Countries worldwide have deployed mass COVID-19 vaccination drives, but there are people who are hesitant to receive the vaccine. Studies assessing the factors associated with COVID-19 vaccination hesitancy are inconclusive. This study aimed to assess the global prevalence of COVID-19 vaccination hesitancy and determine the potential factors associated with such hesitancy. We performed an organized search for relevant articles in PubMed, Scopus, and Web of Science. Extraction of the required information was performed for each study. A single-arm meta-analysis was performed to determine the global prevalence of COVID-19 vaccination hesitancy; the potential factors related to vaccine hesitancy were analyzed using a Z-test. A total of 56 articles were included in our analysis. We found that the global prevalence of COVID-19 vaccination hesitancy was 25%. Being a woman, being a 50-year-old or younger, being single, being unemployed, living in a household with five or more individuals, having an educational attainment lower than an undergraduate degree, having a non-healthcare-related job and considering COVID-19 vaccines to be unsafe were associated with a higher risk of vaccination hesitancy. In contrast, living with children at home, maintaining physical distancing norms, having ever tested for COVID-19, and having a history of influenza vaccination in the past few years were associated with a lower risk of hesitancy to COVID-19 vaccination. Our study provides valuable information on COVID-19 vaccination hesitancy, and we recommend special interventions in the sub-populations with increased risk to reduce COVID-19 vaccine hesitancy.

Global Predictors of COVID-19 Vaccine Hesitancy: A Systematic Review

Background: vaccine hesitancy is defined as a delay in the acceptance or refusal of vaccination, even though immunisation is a determinant in reducing the mortality and morbidity associated with Coronavirus Disease 2019 (COVID-19). Aim: to identify and analyse the predictors of COVID-19 vaccine acceptance and/or hesitancy. Methods: a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Keywords: vaccine and (COVID or SARS) and (acceptance or acceptability or willingness or hesitancy or refusal) and (multivariate or regression) and (questionnaire or survey) and national. Databases/resources: PubMed, DOAJ, SciELO and b-on. Timeframe: March 2020–2022. Inclusion criteria: general population, questionnaire-based, calculation of a multivariate regression model and national studies. Quality assessment: application of the National Heart, Lung, and Blood institute (NHLBI) tool. Results: a total of 37 studies were selected, whose overall rate was fair. The most predominant predictors of vaccine hesitancy were a lower perceived risk of getting infected, a lower level of institutional trust, not being vaccinated against influenza, lower levels of perceived severity of COVID-19, or stronger beliefs that the vaccination would cause side effects or be unsafe. Discussion and conclusion: the identified predictors can be used to design tailored health policies and/or public health interventions, or to evaluate subjects’ vaccine hesitancy.

South African University Staff and Students’ Perspectives, Preferences, and Drivers of Hesitancy Regarding COVID-19 Vaccines: A Multi-Methods Study

COVID-19 vaccine hesitancy poses a threat to the success of vaccination programmes currently being implemented. Concerns regarding vaccine effectiveness and vaccine-related adverse events are potential barriers to vaccination; however, it remains unclear whether tailored messaging and vaccination programmes can influence uptake. Understanding the preferences of key groups, including students, could guide the implementation of youth-targeted COVID-19 vaccination programmes, ensuring optimal uptake. This study examined university staff and students’ perspectives, preferences, and drivers of hesitancy regarding COVID-19 vaccines. A multi-methods approach was used—an online convenience sample survey and discrete choice experiment (DCE)—targeting staff and students at the University of KwaZulu-Natal, South Africa. The survey and DCE were available for staff and students, and data were collected from 18 November to 24 December 2021. The survey captured demographic characteristics as well as attitudes and perspectives of COVID-19 and available vaccines using modified Likert rating questions adapted from previously used tools. The DCE was embedded within the survey tool and varied critical COVID-19 vaccine programme characteristics to calculate relative utilities (preferences) and determine trade-offs. A total of 1836 staff and students participated in the study (541 staff, 1262 students, 33 undisclosed). A total of 1145 (62%) respondents reported that they had been vaccinated against COVID-19. Vaccination against COVID-19 was less prevalent among students compared with staff (79% of staff vs. 57% of students). The vaccine’s effectiveness (22%), and its safety (21%), ranked as the two dominant reasons for not getting vaccinated. These concerns were also evident from the DCE, with staff and students being significantly influenced by vaccine effectiveness, with participants preferring highly effective vaccines (90% effective) as compared with those listed as being 70% or 50% effective (β = −3.72, 95% CI = −4.39 to −3.04); this characteristic had the strongest effect on preferences of any attribute. The frequency of vaccination doses was also found to have a significant effect on preferences with participants deriving less utility from choice alternatives requiring two initial vaccine doses compared with one dose (β = −1.00, 95% CI = −1.42 to −0.58) or annual boosters compared with none (β = −2.35, 95% CI = −2.85 to −1.86). Notably, an incentive of ZAR 350 (USD 23.28) did have a positive utility (β = 1.14, 95% CI = 0.76 to 1.53) as compared with no incentive. Given the slow take-up of vaccination among youth in South Africa, this study offers valuable insights into the factors that drive hesitancy among this population. Concerns have been raised around the safety and effectiveness of vaccines, although there remains a predilection for efficient services. Respondents were not enthusiastic about the prospect of having to take boosters, and this has played out in the roll-out data. Financial incentives may increase both the uptake of the initial dose of vaccines and see a more favourable response to subsequent boosters. Universities should consider tailored messaging regarding vaccine effectiveness and facilitate access to vaccines, to align services with the stated preferences of staff and students.

Public Preferences for Policies to Promote COVID-19 Vaccination Uptake: A Discrete Choice Experiment in The Netherlands

OBJECTIVES

The COVID-19 pandemic forms an unprecedented public health, economic, and social crisis. Uptake of vaccination is critical for controlling the pandemic. Nevertheless, vaccination hesitancy is considerable, requiring policies to promote uptake. We investigate Dutch citizens' preferences for policies that aim to promote vaccination through facilitating choice of vaccination, profiling it as the norm, making vaccination more attractive through rewards, or punishing people who reject vaccination.

METHODS

We conducted a discrete choice experiment in which 747 respondents were asked to choose between policies to promote vaccination uptake and their impacts on the number of deaths, people with permanent health problems, households with income loss, and a tax increase.

RESULTS

Respondents generally had a negative preference for policies that promote vaccination. They particularly disliked policies that punish those who reject the vaccine and were more favorable toward policies that reward vaccination, such as awarding additional rights to vaccinated individuals through vaccination passports. Respondents who reject vaccination were in general much more negative about the policy options than respondents who consider accepting the vaccine. Nevertheless, vaccination passports are supported by both respondents who accept the vaccine, those who reject vaccination, and those who are unsure about vaccination.

CONCLUSIONS

This study provides concrete directions for governments attempting to increase the vaccination uptake in ways that are supported by the public. Our results could encourage policy makers to focus on policy options that make vaccination easier and reward people who take the vaccine, as especially the implementation of vaccination passports was supported.

Acceptance and willingness to purchase a hypothetical COVID-19 vaccine in a region under Shariah law: A cross-sectional study in Aceh, Indonesia

Vaccines are urgently needed to control the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to determine the acceptance of and willingness to purchase a hypothetical COVID-19 vaccine in the general population of Aceh, a holistic Shariah law implementation province in Indonesia. An online cross-sectional study was conducted using a quota sampling technique between 1 to 24 September 2021. To determine hypothetical vaccine acceptance, respondents were asked if they were willing to accept vaccines with combinations of either 50% or 95% effectiveness and either 5% or 20% risk of adverse effects. Willingness to purchase was assessed by asking whether the participants would pay for such vaccines at certain price points. Logistic regression analysis was used to assess the associated determinants. Out of 377 respondents included in the final analysis, 86.5% were willing to accept a COVID-19 vaccine with 95% effectiveness and 5% adverse effects. The acceptance rate dropped to 45.1% if the risk of adverse effects was 20%. Vaccines with 50% effectiveness and 5% adverse effects were acceptable to 42.2% but the acceptance went down to 17.2% if the risk of adverse effects increased to 20%. Multivariate analysis found that men were twice as likely to accept a vaccine with 95% effectiveness and 5% adverse effects compared to females (aOR: 2.01; 95% CI 1.05-3.86). We found that 156/377 (41.3%) of respondents were willing to purchase a COVID-19 vaccine and of these participants 71.1% were willing to pay between Indonesian Rupiah (IDR) 50,000-150,000 (US$ 3.33-10.00). In conclusion, the acceptance rate of a hypothetical COVID-19 vaccine varied based on effectiveness and the risk of adverse effects.

Personal and contextual determinants of COVID-19 vaccination intention: a vignette study

BACKGROUND

This vignette study explores which factors contribute to higher COVID-19 vaccination intentions.

METHODS

Between the 4^th-11 January 2021, we recruited 15,901 Belgian citizens (M_age = 50.11 years, range 18-100) through convenience sampling to participate in a vignette study. In each vignette, we manipulated contextual determinants consisting of different factors. Each participant rated six vignettes in terms of the outcomes 'vaccination intention' and 'recommendation to others.' Finally, we explored the benefits of tailored communication by examining whether these ratings depended upon citizens' initial motives for vaccination.

RESULTS

Participants are most likely to accept a vaccine when they expect no or only small side effects, when the vaccine offers a 95% protection, and when people can no longer infect others (p < 0.001). The possibility to receive the vaccine at home or at the GP's office, highlighting that most citizens are willing to get vaccinated, and emphasizing the protective benefits for others yielded additional positive effects (p < 0.001). Results showed that tailored communication has a small but significant effect, especially for individuals high on distrust-based amotivation (p < 0.01).

CONCLUSION

In addition to vaccine characteristics, there is room for policymakers to respond to those determinants that fall under their control and can thus be highlighted within communication campaigns.

Discussion of the Trust in Vaccination against COVID-19

The COVID-19 pandemic has introduced serious challenges to global public health security, and the benefits of vaccination via public health interventions have been recognized as significant. Vaccination is an effective means of preventing and controlling the spread of COVID-19. However, trust is a major factor that influences vaccine hesitancy; thus, the distrust of vaccination has hindered the popularization of COVID-19 vaccines. This paper aims to discuss the main problems and the role of trust in the vaccination against COVID-19 to effectively promote and implement policy to promote the acceptance of COVID-19 vaccines.

First COVID-19 Booster Dose in the General Population: A Systematic Review and Meta-Analysis of Willingness and Its Predictors

The emergence of breakthrough infections and new highly contagious variants of SARS-CoV-2 threaten the immunization in individuals who had completed the primary COVID-19 vaccination. This systematic review and meta-analysis investigated, for the first time, acceptance of the first COVID-19 booster dose and its associated factors among fully vaccinated individuals. We followed the PRISMA guidelines. We searched Scopus, Web of Science, Medline, PubMed, ProQuest, CINAHL and medrxiv from inception to 21 May 2022. We found 14 studies including 104,047 fully vaccinated individuals. The prevalence of individuals who intend to accept a booster was 79.0%, while the prevalence of unsure individuals was 12.6%, and the prevalence of individuals that intend to refuse a booster was 14.3%. The main predictors of willingness were older age, flu vaccination in the previous season, and confidence in COVID-19 vaccination. The most important reasons for decline were adverse reactions and discomfort experienced after previous COVID-19 vaccine doses and concerns for serious adverse reactions to COVID-19 booster doses. Considering the burden of COVID-19, a high acceptance rate of booster doses could be critical in controlling the pandemic. Our findings are innovative and could help policymakers to design and implement specific COVID-19 vaccination programs in order to decrease booster vaccine hesitancy.